Although the constancy of genetic information is central, genomes are surprisingly unstable. Transposable elements, i.e. discrete DNA segments that can move between many non-homologous positions, are widespread, having been found in virtually all organisms. Indeed, in some genomes, transposable element sequences are the predominant component: strikingly, about 45% of the human genome is composed of transposable element sequences. The consequences of transposable element movement are many: insertion can result in alterations in host gene expression, in the covalent linkage of element-encoded determinates to host DNA, for example the joining of antibiotic resistance determinants to plasmids that can move between cells or the integration of retroviral DNA into host genomes. Also, gaps in the donor DNA following element excision are often not restored to their pre- transposon state. Moreover, DNA breaks can result in DNA damage signals. We propose to study at the molecular and biochemical level how transposition is controlled by its host and how the host responds to the movement of transposable elements, a potentially lethal event because it involves DNA breakage and joining. We will study the bacterial transposon Tn7 in E. coli and the insect transposon Hermes in S. cerevisiae and in Drosophila. We will probe how the assembly of particular nucleoprotein in complexes can control transposition though in vitro dissection of Tn7 transposition and will dissect the role of host functions in Tn7 transposition through the isolation and characterization of host mutants that alter transposition. We will also probe Hermes transposition in yeast and flies through the isolation of mutants that alter its movement. We will also examine how the transposase-mediated breaks can lead to chromosomal rearrangements, i.e. genetic instability. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM076425-02
Application #
7176206
Study Section
Molecular Genetics A Study Section (MGA)
Program Officer
Dearolf, Charles R
Project Start
2006-03-01
Project End
2010-02-28
Budget Start
2007-03-01
Budget End
2008-02-29
Support Year
2
Fiscal Year
2007
Total Cost
$310,210
Indirect Cost
Name
Johns Hopkins University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Zordan, Rebecca E; Beliveau, Brian J; Trow, Jonathan A et al. (2015) Avoiding the ends: internal epitope tagging of proteins using transposon Tn7. Genetics 200:47-58
Choi, Ki Young; Spencer, Jeanelle M; Craig, Nancy L (2014) The Tn7 transposition regulator TnsC interacts with the transposase subunit TnsB and target selector TnsD. Proc Natl Acad Sci U S A 111:E2858-65
Choi, Ki Young; Li, Ying; Sarnovsky, Robert et al. (2013) Direct interaction between the TnsA and TnsB subunits controls the heteromeric Tn7 transposase. Proc Natl Acad Sci U S A 110:E2038-45
Li, Xianghong; Ewis, Hosam; Hice, Robert H et al. (2013) A resurrected mammalian hAT transposable element and a closely related insect element are highly active in human cell culture. Proc Natl Acad Sci U S A 110:E478-87
Guo, Yabin; Park, Jung Min; Cui, Bowen et al. (2013) Integration profiling of gene function with dense maps of transposon integration. Genetics 195:599-609
Woodard, Lauren E; Li, Xianghong; Malani, Nirav et al. (2012) Comparative analysis of the recently discovered hAT transposon TcBuster in human cells. PLoS One 7:e42666
Gangadharan, Sunil; Mularoni, Loris; Fain-Thornton, Jennifer et al. (2010) DNA transposon Hermes inserts into DNA in nucleosome-free regions in vivo. Proc Natl Acad Sci U S A 107:21966-72
Holder, Jason W; Craig, Nancy L (2010) Architecture of the Tn7 posttransposition complex: an elaborate nucleoprotein structure. J Mol Biol 401:167-81
Mitra, Rupak; McKenzie, Gregory J; Yi, Liang et al. (2010) Characterization of the TnsD-attTn7 complex that promotes site-specific insertion of Tn7. Mob DNA 1:18
Mitra, Rupak; Fain-Thornton, Jennifer; Craig, Nancy L (2008) piggyBac can bypass DNA synthesis during cut and paste transposition. EMBO J 27:1097-109

Showing the most recent 10 out of 11 publications